EXCLUSIVE — ISSA TO ENDORSE ROMNEY: Darrell Issa, the chairman of the House Oversight and Government Reform Committee, will endorse Mitt Romney ahead of tonight's debate in Florida. Issa's battles with the White House have made him a hero to conservatives. The endorsement is doubly significant because Issa backed John McCain last time, and his rags-to-riches story gives him credibility with the GOP donor class. Romney sees him as an important asset in California. From Chairman Issa's forthcoming statement: "The country would be well served to have someone who knows how the economy works and has worked in the private sector. President Obama never worked in the real economy. We can't afford to have another president who has spent his career outside the real economy."

Romney's campaign will also announce the endorsement from former New Hampshire state Senate President Ed Dupont this morning. A major McCain endorser in 2008, Dupont is the second former New Hampshire Senate president to back Romney.

FIRST IN SCORE — RON PAUL'S MILLION-DOLLAR AD BUY: Paul will start a three-week, $1 million ad buy today — his biggest of the campaign. POLITICO's Dan Hirschhorn reports that the buy will include three different spots, running on Fox News nationally and on local broadcast in all four early states. It coincides with a stepped-up direct-mail and Internet ad campaign, as Paul senses opportunity at a time when he has cash and the airwaves are mostly devoid of paid media. "We think that now is the time to break through," Paul political guru Jesse Benton says. The first ad, a 60-second spot that will run for 10 days, touts Paul's work on behalf of military vets: "Ron Paul is a veteran's best friend." Look out for another positive spot on foreign policy soon and a third hitting Rick Perry later. Watch bit.ly/pcdmr7.

TOP TALKER — NEW HAMPSHIRE POLL SHOWS ROMNEY'S FIREWALL HOLDING: "Mitt Romney has maintained his decisive lead in New Hampshire while Jon Huntsman has begun to gain traction in a must-win state for both, according to a new Suffolk University/WHDH-TV survey," Juana Summers writes. "In the poll of 400 likely Republican primary voters, the former Massachusetts governor is at 41 percent — 27 points ahead of his nearest rival. … National poll frontrunner Rick Perry, who's focused his campaign elsewhere after a short swing through the state immediately after jumping into the race last month, is in fourth, with 8 percent." politi.co/mUAJb5.

FLORIDA, FLORIDA, FLORIDA: Morning Score is brought to you for the rest of this week through a partnership between POLITICO and the St. Petersburg Times, home to Florida's top team of political journalists. Tonight is the Fox News-Google debate from 9-11 p.m. Friday is the first Florida-based Conservative Political Action Conference. It all culminates with a straw poll Saturday.

ADAM SMITH MINDMELD — THE ST. PETE TIMES POLITICAL EDITOR TELLS US WHAT'S ON HIS MIND: Presidential debates are about the national TV audience, of course. But just as last week's lively tea party debate audience helped set the tone in Tampa, tonight's audience in Orlando is significant. Watching at the Orange County Convention Center will be nearly 3,500 registered Florida GOP delegates who on Saturday will hold their mock primary election, the Presidency 5 straw poll. This debate audience is the grass-roots backbone of the Florida GOP, so debate performances will directly affect Saturday's vote. Perry is favored, but don't underestimate Romney's and Paul's support in the crowd.

THE BATTLE OF ORLANDO — WHAT TO WATCH IN TONIGHT'S DEBATE: Here are 10 things that the political teams at the St. Petersburg Times and POLITICO will be watching:

St. Petersburg Times:

1. With the Israeli-Palestinian dispute back on the front burner, Perry has an opportunity (or challenge) to show substance on foreign policy. Will he?

2. We can assume Mitt Romney will go after Perry again on Social Security, but will any other Republicans back Romney up or chastise him for "scaring seniors"?

3. What new issues will arise? How about a hot-button one for Florida — Cuba? Tampa and Fort Lauderdale recently started direct flights to Cuba. Does that bother the candidates and do they sound like they know what they're talking about?

4. After her HPV/retardation comments, can Michele Bachmann demonstrate she's still more relevant in the contest than Rick Santorum?

2. How does Gary Johnson, the little-known former governor of New Mexico who got a last-minute invite, choose to use his time in front of the cameras?

3. Which version of the Texas governor shows up — the more aggressive Perry from the Simi Valley debate or the subdued Perry from Tampa?

4. Perry's semi-dovish Afghanistan answer in last week's debate led to criticism from Romney and Huntsman, and a clarification from a foreign policy aide. Will Perry take a more hawkish tack on Afghanistan if pressed?

5. Santorum said Tuesday that he's frustrated he hasn't had a direct opportunity to attack Romneycare yet. Will he tonight?

DEMOCRATS MOBILIZE — HOW THEY ARE BRACKETING THE DEBATE

SNEAK PEEK — PRIORITIES USA MAKES CASE FOR OBAMA'S DEFICIT PLAN: The pro-Obama super PAC Priorities USA will make the case in a memo today that Democrats are winning the debate over taxes, arguing that voters have a "fundamental belief" that wealthy Americans should be paying more than they do. The document is the first in a series of "Priorities Points" memos from the Democratic group, which will offer regular polling analysis and other observations on the political landscape. In the inaugural edition — released three days after President Barack Obama outlined his proposal for upper-income tax increases — Priorities USA points to a raft of survey data showing Americans are supportive of raising taxes on the wealthy. Read the memo: politi.co/oHAyvz.

OUT THIS MORNING — DNC CHAIR SAYS CANDIDATES WILL OFFER NO NEW IDEAS: Democratic National Committee Chair Debbie Wasserman Schultz has written a memo previewing the debate. Her takeaway message: "What you will not hear them talk about, and what they refused to talk about for the previous five debates, is a single new idea or proposal that will create jobs in Florida or around the country or help middle-class Americans get back on their feet." Read the 1,400-word memo: politi.co/nkwfLF.

PROTECT YOUR CARE — NEW AD HITS REPUBLICANS ON MEDICARE: The group created to defend the health care law is going up today with a new TV ad called "Listen" that will run in the Orlando market-broadcast and cable-from Thursday to Sunday, including spots during the debate. They will also beef up an online ad buy started last week. A source says about $70,000–$75,000 is being invested in the campaign. The ad will be available here: bit.ly/oCKP5z.

AMERICAN BRIDGE — ATTACKS ROMNEY AS A FLIP-FLOPPER: The American Bridge 21st Century PAC is releasing a Web ad this morning highlighting a Boston Globe article on Romney's investment worth up to half a million dollars in a mutual fund that is nearly half Fannie, Freddie and Federal Home Loan Bank notes. bit.ly/oSoslq

THE PRESIDENT HIMSELF — PUSHING THE JOBS ACT IN CINCINNATI: At 2:30 p.m., per the White House, President Obama will "deliver remarks at the Brent Spence Bridge, that spans Kentucky and Ohio, urging Congress to pass the American Jobs Act now."

MORE FROM THE SUNSHINE STATE

MECHANICS OF THE DEBATE: Fox explains how it has culled more than 18,000 questions offered via text and video on YouTube: fxn.ws/pJWdfK.

2. Lenny Curry. The Jacksonville Republican became state GOP chairman after the sudden death of David Bitner this month.

3. Agriculture Commissioner Adam Putnam. The former congressman from Bartow is one of the brightest lights in the Florida GOP and probably a future governor. He's neutral so far in the presidential race.

4. State Sen. John Thrasher. The former House Speaker is among Mitt Romney's top allies.

5. Pollster Tony Fabrizio. A top adviser to Gov. Rick Scott.

FLORIDA INTEL — WHAT YOU NEED TO KNOW ABOUT GOV. RICK SCOTT: Four years ago, the field of Republican presidential candidates descended on Florida desperate for the endorsement of then-Gov. Charlie Crist. Now, its tea party favorite Rick Scott leading the state party. Scott's approval rating is about half of what Crist's was at his most popular. But the new boss' aggressive brand of conservatism plays well among primary voters. Scott will listen to pitches from presidential candidates but won't endorse. During his brutal primary last year, the rookie politician took on much of the state party, the Republican Governor's Association and GOP allies in the Tallahassee lobby corps. Scott wants to see a fair fight.

FOUR LESSONS FROM THE LAST DEBATES:

1. Perry is willing to challenge the axiom that a politician should try not to engage lesser-known rivals.

2. Bachmann is willing to attack Perry on personal terms. The Minnesota congresswoman brought up Merck and went after the governor for crony capitalism with little prompting.

3. Perry is best on offense, but is uncomfortable and unfamiliar with responding to attacks from his right flank.

4. Perry performed significantly better in the first half of the last two debates, suggesting he's most vulnerable to attack and gaffe-prone near the end.

IMMIGRATION — AD ON FOX WILL PUSH CANDIDATES TO TAKE A HARDER LINE: NumbersUSA is expanding its campaign to link immigration levels to unemployment by airing a commercial on Fox News during tonight's debate. The group wants to reduce legal immigration. They have already been running the ad in targeted districts around the country. They are not disclosing the size of the buy. Watch it: bit.ly/n3mvlh. More on what they want: bit.ly/rotcaa.

DOWN UNDER — TRUMP SPOTTED IN SYDNEY: A bunch of the candidates are set to attend a Faith and Freedom Coalition kickoff event at the Rosen Centre Hotel near the debate site at 3 p.m. The Donald is giving paid speeches in Australia, but he has recorded a special video greeting for that rally. It is scheduled to play right before Perry addresses the crowd. A tipster emailed this photo: politi.co/qFOUeK.

BIG DEM RECRUITMENT — GULLESON TO RUN FOR HOUSE IN N.D.: Pam Gulleson will announce her campaign to run for the open North Dakota House seat today. There have been rustlings that she is intending to run, but Morning Score has learned that Gulleson has locked down the support of the state's three most prominent Democrats: Kent Conrad, Byron Dorgan and Earl Pomeroy. A Democrat e-mails us: "Pam is THE recruit for this seat, and her experience and reputation puts ND-AL on the map as a barnburner. A rough-and-tumble primary fight is expected from the GOP and their candidate will be picked by convention-which means it will be a race for the extreme right." See the forthcoming press release announcing her candidacy, which includes excerpts from the speech: politi.co/qifUr7.

NORTH DAKOTA SENATE — DEM POLLING SUGGESTS BERG WEAKNESS: The DSCC is releasing a memo this morning from Democratic pollster Geoff Garin of the Garin-Hart-Yang Research Group that argues Republican Senate candidate Rick Berg is weak and that North Dakota's open Senate race should be viewed as competitive. From a three-page memo: "In a generic trial heat, just 44% say they are inclined to elect Rick Berg, whereas 40% prefer electing a Democrat. Among the remaining 16% who are undecided, more than eight out of 10 are either Democrats or independents." (The survey was conducted from August 14-16, and there was speculation in ND as recently as the other day that Gulleson might run for Senate. Her decision to run for the House suggests she thinks it will be easier to win Berg's open seat than to beat Berg.) The memo: politi.co/mZjeS2.

SNEAK PEEK — DEMOCRACY CORPS POLL HIGHLIGHTS VULNERABLE HOUSE REPUBLICANS: Democracy Corps surveyed the districts of 60 incumbent House Republicans, most of whom represent districts claimed by Obama in 2008. Fifteen months out from the election, almost half (49 percent) of all voters in these Republican districts now say that they "can't vote to reelect" their representatives. Half of all voters (51 percent) agree with the statement: "The more I hear from my representative in Congress, the less I like." That's a seven point jump since March. Clinton pollster Stanley Greenberg, the group's cofounder and CEO of Greenberg Quinlan Rosner, will use these numbers to on a conference call this afternoon that Republicans holding their majority is anything but certain. Full results will post here later: bit.ly/qRAP0s.

Greenberg's results may signal trouble, but Dan Hirschhorn reports in the story leading POLITICO's site this morning that Democratic operatives and members feel increasingly bearish about their chances to recapture the House: politi.co/r3Bmdh.

OHIO SENATE — DSCC TO HIT MANDEL ON DISCLOSURES: Ohio Republican Senate candidate Josh Mandel is in Washington today for a fundraiser with John Boehner and Rob Portman. The Democratic Senatorial Campaign Committee will use the trip to attack the state treasurer for not filing his personal financial disclosure with the Senate Office of Public Records as required. Their hit, to go out later and focus on Ohio press, includes a Google map from the site of the fundraiser to the office where he could personally turn in the form. Mandel's campaign has said that the delay has been caused by figuring out how to properly report his wealthy wife's assets. Democrats think they can use it as a data point to paint him as "ethically challenged."

EXCLUSIVE — BOLTON ENDORSES ANN WAGNER IN MO-2: Former U.N. ambassador John Bolton, who recently announced he will not run for president after keeping the possibility open for months, will endorse Ann Wagner today in her contested Republican House primary battle in Missouri. This is his first endorsement of any congressional candidate this cycle. He says in a statement: "She has defeated liberals for decades as a party leader and activist and now, for the first time, it is time for all conservatives to stand up for Ann and send her to Congress."

2012 VEEPSTAKES — RUBIO HIRES ALEX CONANT: The spokesman for Tim Pawlenty's presidential campaign, Alex Conant, will become Sen. Marco Rubio's press secretary on Oct. 3. This is a huge get for Rubio as he increases his national visibility and continues to audition for a shot at the vice presidency next year. bit.ly/qnfLrb

CODA — TWEET OF THE DAY: "Gov Perry must... MUST... learn how to correctly pronounce NUCLEAR ... not NUQUILAR ... if he is going to be taken seriously. He MUST." — Kiss bassist Gene Simmons, who is actually supporting Perry. politi.co/mVF1Nx